The invention relates to a compound material comprising fibers which are embedded in a thermoplastic matrix, to a method for its manufacture and to uses of the compound material.
DE-A-41 21 915 describes a pressure impregnation, namely a method for impregnating an endless reinforcement fiber strand with a thermoplastic polymer. In this method the fiber strand is first impregnated with the particles in a bath which contains a dispersion of solid fiber thermoplastic particles. After the impregnation bath the dispersing agent is evaporated out of the impregnated fiber strand in a drying oven. Then the dry fiber strand is passed through a melting furnace in which the particles melt. After a consolidation a fiber compound material in the form of a small band with a solid thermoplastic or polymer matrix is present. Sections can be manufactured of a bundle of such small bands by means of a pultrusion. Through the pultrusion process, in which the thermoplastic is temporarily melted again, a dense, pore-poor polymer matrix arises.
Section-shaped compound materials are suitable for reinforcing components which are used in building construction, vehicle construction, lightweight construction or the construction of apparatuses and devices, with the components being in particular ceilings or walls of buildings. The section is applied with a bonding means, i.e. with an adhesive, to the component for reinforcement. In a fiber compound material with a thermoplastic matrix there is the problem that the usual bonding means adhere poorly to thermoplastics. In a stressing of the reinforced component the connection between the section and the bonding means would loosen.
An object of the invention is to create a compound material in which fibers are embedded in a thermoplastic matrix and which can be secured with a usual bonding means on a component in such a manner that the expected reinforcement function results. This object is satisfied by a compound material according to the present invention.
The compound material comprising fibers which are embedded in a thermoplastic matrix has a free surface to be treated. It has one or more capillary spaces which extend between the fibers, which are at least partly formed by communicating pores and which are open towards the surface to be treated. An average diameter of the pores is greater than, equal to or not substantially less than the fiber diameter.
Advantageous embodiments of the compound material in accordance with the invention, corresponding manufacturing methods, and uses of the compound material in accordance with the invention are described below.
The invention will be explained in the following with reference to the drawings.